RuleSentry is a beginner-level cybersecurity project that I built using Python to understand how firewall rules and traffic monitoring work in a real environment.
The main idea behind this project was to simulate how a firewall makes decisions based on rules and how network traffic can be analyzed. Instead of just allowing or blocking traffic, I tried to make it a bit more realistic by also identifying suspicious activity and marking it as MONITOR with a risk level.
Project Overview
In this project, the system allows users to create their own firewall rules and test different types of network traffic. Based on the rules and some basic logic, the system decides whether the traffic should be:
ALLOW – normal traffic MONITOR – suspicious traffic BLOCK – restricted or dangerous traffic
It also assigns a risk level (Low, Medium, High) and keeps a record of all traffic events.
Features
Add custom firewall rules (direction, protocol, port, action) View all configured rules Analyze traffic using user input Decision output: ALLOW / MONITOR / BLOCK Risk level classification Detection of sensitive ports like SSH, RDP, SMB, FTP, and Telnet Event/alert history Generate a report file with results
Example Scenarios
Here are a few cases I tested:
Blocking inbound RDP traffic (port 3389) → BLOCK Allowing outbound HTTPS traffic (port 443) → ALLOW Inbound SSH traffic (port 22) without a rule → MONITOR
Technologies Used
Python Command Line Interface
What I Learned
Through this project, I learned: how firewall rules are created and used how traffic can be analyzed based on different conditions how sensitive ports can indicate potential risks how to build a Python program using functions, lists, and dictionaries how event logging and simple risk classification works in security systems
Report
The full project report is included in this repository.
Final Thoughts
This project helped me understand the basics of firewall logic and traffic analysis in a practical way. It also improved my Python skills and gave me a better idea of how security systems make decisions.
This is one of the projects I built as part of improving my hands-on experience in cybersecurity.